The multitude of distributed nomadic electrical appliances presents specific needs in respect of its energy storage, bringing about distinct supply voltages and energy storage capacities for most of these appliances. The manufacturing cost of electrochemical cells of batteries being relatively high, the approach generally chosen by battery manufacturers is to design a battery exhibiting a specific dimensioning for the electrical appliance to be powered. Thus, the scale effect is relatively limited in most cases, thus constituting an impediment to a drop in the manufacturing cost of batteries and to their spread. The limitation of the scale effect is particularly noticeable for power batteries.
Furthermore, batteries are dimensioned to take into account the most extreme cases of operation and are thus usually overdimensioned for daily use by users. The range of a vehicle with electric motorization is for example defined by the capacity of its battery, this capacity being dimensioned by an appropriate number of electrochemical cells connected electrically in series and in parallel. For example, a battery can be dimensioned for a range of 80 km for a bike with electrical assistance, whereas in practice the user undertakes its recharging every 15 km on account of its daily use. Consequently, the user purchases an overdimensioned battery which is therefore more expensive in relation to its actual use.
There therefore exists a need for a solution making it possible to standardize the electrochemical cells of various batteries, so as to be able on the one hand to benefit from a scale effect for various applications, and to be able on the other hand to adapt the number of electrochemical cells to the user's actual needs. These results must be obtained while preserving a system requiring a minimum of precautions of usage and immediate availability of the electric load powered by such a supply.
Moreover, it may be noted that the document JP2001-086662 describes an electrical power supply system with an interconnection interface for selectively connecting several electrical energy storage modules in parallel. A control circuit determines the number of modules connected to the interface. The power supply of a load is managed as a function of the determined number of modules.
Furthermore, it may be noted that the document JP2008-118790 describes an electrical power supply system comprising several branches connected in parallel. A drive circuit controls the current drawn towards the load by each of the branches so as to balance the states of charge of the various branches.